Update notes to indicate to use jitpack

f-droid does not allow libraries pulled from non-listed maven repositories, thus a build which tries to consume this package from Invent would fail in f-droid: https://gitlab.com/fdroid/fdroiddata/-/jobs/3654530159#L236

Found unknown maven repo 'https://invent.kde.org/api/v4/projects/72/packages/maven' at settings.gradle

jitpack is an approved repo, and should give us everything we need. Plus, it's a very slick and automated system.